1. Field of the Invention
The present invention relates to a method of manufacturing motors.
2. Description of the Related Art
An example of a stator of a conventional motor is shown in FIG. 29(A). In the known motor, a plurality of Y-shaped field poles 11 are formed on an inside surface 10a of a stator body 10. A coil 14 is wound around each of the field poles 11. Generally, an automatic winding machine is often used to wind a coil on the stator body 10. An example of the automatic winding machine is disclosed in Japanese non-examined laid-open Patent Publication No. 2000-14098. As shown in FIG. 29(B), the known winding machine winds a coil winding a number of turns on the field pole 11 into the coil receiving parts, such as coil winding n1 of a first turn and coil winding n2 of a second turn, one after another. Thus, coils 14 of many turns are installed on the field pole 11.
In the above-mentioned known art, the coil winding is wound on the field core 13 of the field pole 11 one turn at a time. Therefore, as the number of turns of the coil winding increases, as shown in FIG. 29(C), coil windings n50, n51 may possibly not be retained by the field pieces 12 of the field pole 11 and come away from the field pole 11. In order to prevent this problem, the number of turns of the coil winding is restricted according to the length of the pole pieces 12 of the field pole 11. On the other hand, it is important to secure an adequate number of turns of the coil winding on the stator body 10 in order to maintain a high output of the motor. Therefore, a more effective technique of installing coil winding is desired.